This invention pertains to a cardiac resuscitation instrument, and more particularly, to a cannula-type resuscitation instrument adapted for transthoracic insertion into and through the wall of a person's heart.
As is well known, cardiac resuscitation is an operation which must be performed extremely quickly, not only to save a person's life, but also to prevent irreversible brain and heart damage. Conventional resuscitation steps take several forms, including so-called external heart massage, injection of medications into the heart, and electrical pacing of the heart.
A general object of the present invention is to provide a novel transthoracic, cannula-type cardiac resuscitation instrument which facilitates rapid, "one-shot" insertion and placement in the wall of a heart, and which thereafter facilitates both immediate injection of medications directly into the heart, as well as electrical pacing of the heart.
Featured in the invention, according to a preferred embodiment thereof, is an elongated flexible tube whose central passage permits free axial insertion and withdrawal of a catheter-like needle--this tube being somewhat shorter than the needle with which it is intended to be used. Mounted on the tube adjacent its distal end are two axially spaced inflatable-deflatable balloons which are positioned on opposite sides of an exposed electrically conductive expanse. Passages are provided in the wall of the tube for enabling selective and independent inflation and deflation of the balloons, and also for carrying a conductor which is connected to the just-mentioned conductive expanse.
During use of this apparatus, the catheter needle, or the like, is inserted into the tube, with the distal end of the needle exposed and extending beyond the distal end of the tube. The needle tip acts as a means for puncturing a person's chest and heart walls, with the body of the prong in the needle acting as a rigid carrier for the tube during its insertion.
As will be explained more fully below, following penetration of a heart wall, the balloons are inflated, one after another, to lock the tube against axial retraction from the heart wall, and also to position the conductive expanse (which is between the balloons) so as properly to engage the heart wall. Thereafter, the needle may be withdrawn.
Then, with the use of a conventional electrical heartpacing source, one output terminal of this source may be connected to supply pulses to the expanse on the tube, and the other output terminal connected to another electrode which is suitably attached to the outside of a person's body. Further, the central axial passage through the tube may be used for the immediate injection of desired medications into the heart cavity.
Various other objects and advantages which are attained by the invention will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings.